Measurement system

Abstract

To provide a measurement system that has a measurement unit that uses electrical impedance values, and that can perform accurate measurements by compensating for the influence of wiring resistance. [Solution] A measurement system comprising a measurement unit that uses electrical impedance values ​​and a calculation unit that corrects electrical impedance values ​​using inverse analysis calculations.

Description

[Technical Field]

[0001] The present invention relates to a measurement system. More specifically, it relates to a measurement system that includes a measurement unit using electrical impedance values ​​and is capable of measuring accurate values ​​by compensating for the influence of wiring resistance. [Background technology]

[0002] Flexible sensors, which combine flexibility and thinness, are measurement systems that can be installed in various places such as curved surfaces, moving parts, and skin. Existing flexible sensors generally consist of sheet-like structures with sensors equivalent to the measurement unit using electrical impedance values, either individually or arranged in two dimensions. However, these flexible sensors have the problem of being difficult to use with complex shapes such as spheres.

[0003] Patent Document 1 describes a flexible sensor in which sensors are arranged in a two-dimensional array, capable of acquiring a target physical quantity in two dimensions. While this flexible sensor offers excellent convenience, when installed on complex curved surfaces such as spheres, wrinkles may form, potentially compromising its reliability. Furthermore, providing elasticity to prevent wrinkle formation presents technical challenges.

[0004] Patent Document 2 describes a fiber optic temperature distribution measurement system as a flexible sensor that measures temperature distribution in one dimension, as a system for measuring temperature distribution over long distances. Although this fiber optic temperature distribution measurement system can measure temperature distribution over long distances, it has problems such as high introduction costs due to the need for a Raman spectrometer with high temporal resolution, a large minimum radius of curvature, and low spatial resolution.

[0005] Patent Document 3 discloses a tape-type (ribbon-type) long sensor that can easily accommodate complex shapes. This long sensor can be applied to complex shapes such as spheres and robot fingers, can be attached to clothing, walls, floors, etc., is easy to attach and does not require special skills, does not require the addition of elasticity, thus improving reliability, and has advantages such as being easy to repair. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2018 / 084284 [Patent Document 2] Japanese Patent Publication No. 2017-150987 [Patent Document 3] Japanese Patent Publication No. 2023-023046 [Overview of the project] [Problems that the invention aims to solve]

[0007] To measure a wide variety of data, particularly to acquire previously unmeasured data, numerous sensors are being placed in various locations. Flexible sensors, which offer high installation flexibility and are equipped with multiple sensors, are used as measurement systems for this diverse data. One example of a flexible sensor is the flexible long-range multi-point sensor, which is obtained by forming electrodes and wiring on a long flexible substrate by printing conductive paste and mounting numerous sensor elements for temperature, pressure, illuminance, chemistry, etc. It is used in applications requiring long-range and multi-point measurement and management in factory equipment, pipelines, server rooms, plant factories, air conditioning equipment, etc. Such flexible sensors are thin, lightweight, flexible (bend and stretch), unbreakable when dropped, printable, low-cost, and capable of spatial distribution measurement.

[0008] The measurement method for flexible long-range multi-point sensors detects changes in electrical impedance values, particularly changes in resistance values ​​that occur in response to changes in measurement parameters, and converts these changes into measurement parameters. Since changes in electrical impedance values ​​are detected by changes in current values, the wiring resistance value due to the wiring between the sensor element and the detection unit increases as the distance between them increases. As a result, errors occur between the actual value and the detected value, making it impossible to perform accurate measurements. In particular, flexible long-range multi-point sensors are difficult to wire using copper foil, and since they are wired using conductive paste with a higher resistance than copper foil, the influence of wiring resistance is significant.

[0009] The problem that this invention aims to solve is to provide a measurement system that can perform accurate measurements by compensating for the influence of wiring resistance in a measurement system having a measurement unit that uses electrical impedance values. [Means for solving the problem]

[0010] The inventors of this invention conducted diligent research to solve the above problems and, as a result, discovered that the above problems can be solved by a measurement system having a specific configuration, thus completing the present invention. Specifically, these are as follows: [Section 1] A measurement system comprising a measurement unit that uses electrical impedance values ​​and a calculation unit that corrects electrical impedance values ​​using inverse analysis calculations. [Section 2] The measurement system described in item 1, wherein the calculation unit compensates for the effect of wiring resistance. [Section 3] The measurement system according to item 1 or 2, wherein the measurement unit comprises a flexible ribbon-type multi-point sensor. [Section 4] The measurement system according to any one of items 1 to 3, wherein the measurement unit comprises one or more selected from a temperature sensor, humidity sensor, illuminance sensor, pressure sensor, light sensor, photoelectric sensor, proximity sensor, shear force sensor, magnetic sensor, laser sensor, microwave sensor, strain sensor, gyro sensor, acceleration sensor, geomagnetic sensor, displacement sensor, gas sensor, GPS sensor, ultrasonic sensor, sound sensor, odor sensor, taste sensor, electroencephalogram sensor, current sensor, vibration sensor, pulse wave sensor, electrocardiogram sensor, electromyogram sensor, light intensity sensor, barometric pressure sensor, and biosensor. [Section 5] A program that causes a computer to function as the calculation unit in any one of the measurement systems described in items 1 to 4. [Effects of the Invention]

[0011] The present invention provides a measurement system that can perform accurate measurements by compensating for the influence of wiring resistance in a measurement system having a measurement unit that uses electrical impedance values. In particular, in flexible long-range multi-point sensors with wiring formed by conductive paste, the influence of wiring resistance can be compensated for on the software side by processing the signal using Kirchhoff's laws or approximate solutions, allowing for values ​​closer to the true resistance distribution and enabling more accurate measurements. [Brief explanation of the drawing]

[0012] [Figure 1] A schematic diagram of a measurement system according to one embodiment of the present invention. [Figure 2] A schematic diagram of the measurement unit of a measurement system according to another embodiment of the present invention. [Figure 3] A schematic diagram of the measurement unit of a measurement system according to another embodiment of the present invention. [Figure 4] A schematic diagram of the measurement unit of a measurement system according to another embodiment of the present invention. [Figure 5] This figure shows one embodiment of a method for manufacturing the measuring unit of the measurement system of the present invention. [Figure 6]A flowchart illustrating the operation of the calculation unit in the measurement system of the present invention. [Figure 7] Equivalent circuit model diagram of the measurement section of a conventional passive matrix sensor. [Figure 8] Equivalent circuit model diagram of the measurement unit of a measurement system according to one embodiment of the present invention. [Figure 9] Equivalent circuit model diagram of the measurement unit of a measurement system according to one embodiment of the present invention. [Figure 10] Inverse analysis calculation simulation results from the calculation unit of the measurement system of the present invention. [Figure 11] Inverse analysis calculation simulation results from the calculation unit of the measurement system of the present invention. [Figure 12] A photograph of a measurement system in an embodiment of one specific example of the measurement system of the present invention. [Figure 13] Results of inverse analysis calculation correction in the measurement system of an embodiment according to one specific example of the measurement system of the present invention. [Modes for carrying out the invention]

[0013] The following describes preferred embodiments of the measurement system according to the present invention with reference to the drawings, but the present invention is not limited to the following embodiments. Furthermore, modifications can be made as appropriate without departing from the scope of achieving the effects of the present invention. The use of the same reference numeral in different drawings indicates similar or identical items or features.

[0014] [Measurement System] The measurement system of the present invention comprises a measurement unit that uses electrical impedance values ​​and a calculation unit that corrects electrical impedance values ​​using inverse analysis calculations. The calculation unit in the measurement system of the present invention compensates for the influence of wiring resistance. The measurement system of the present invention can be a flexible ribbon-type multi-point sensor. The measurement system of the present invention can be one or more selected from temperature sensors, humidity sensors, illuminance sensors, pressure sensors, light sensors, photoelectric sensors, proximity sensors, shear force sensors, magnetic sensors, laser sensors, microwave sensors, strain sensors, gyro sensors, acceleration sensors, barometric pressure sensors, geomagnetic sensors, displacement sensors, gas sensors, GPS sensors, ultrasonic sensors, sound sensors, odor sensors, taste sensors, electroencephalogram sensors, current sensors, vibration sensors, pulse wave sensors, electrocardiogram sensors, electromyogram sensors, light intensity sensors, barometric pressure sensors, and biosensors.

[0015] Figure 1 is a schematic diagram of a measurement system according to one embodiment of the present invention. As shown in Figure 1, the measurement system Sys of the present invention comprises at least a measurement unit Mes that uses electrical impedance values ​​and a calculation unit Cal. The measurement unit Mes has a configuration in which a plurality of sensor elements S are mounted on a long substrate 1, and an end module E is provided at one of the longitudinal ends of the long substrate 1.

[0016] <Measurement part> Figures 1 to 4 are schematic diagrams of a measurement system according to one embodiment of the present invention. In Figure 1, Sys represents the measurement system, Mes represents the measurement unit, and Cal represents the calculation unit. The measuring unit Mes has a configuration in which multiple sensor elements S are mounted on a long substrate 1, and an end module E is provided at one of the longitudinal ends of the long substrate 1.

[0017] The measuring section Mes consists of a long substrate and at least m voltage lines V1~V1 provided on the long substrate and extending in the longitudinal direction. m And at least n detection lines D1~D n The wiring has a configuration of 4 to m × n sensor elements mounted on a long substrate, where m and n are each independent integers of 2 or more, the wiring is connected to an end module provided at one end of the long substrate, and each of the sensor elements has at least m voltage lines V1 to V m and at least n detection lines D1~D nThe configuration has voltage lines and detection lines connected in such a way that the combinations of these elements are different from each other.

[0018] For example, the measuring unit Mes of a measuring system according to one embodiment of the present invention shown in Figure 2 is provided on a long substrate (not shown) and has wiring having three (m=3 in Figure 2) voltage lines V1 to V3 and three (n=3 in Figure 2) detection lines D1 to D3 that extend in the longitudinal direction of the long substrate, and nine (m×n=9 in Figure 2) sensor elements S1 to S9 placed on the long substrate, and is connected to an end module E provided at one of the longitudinal ends of the long substrate. Each of the nine sensor elements S is connected to the voltage lines and detection lines such that the combination of the three voltage lines V1 to V3 and the three detection lines D1 to D3 is different from each other.

[0019] In the measurement system of the present invention, the measuring section Mes can be cut at any position from the end module E side, depending on the mode of use, and the space between the end module E and the cut section can be used as the measuring section. The measuring unit Mes of the measuring system according to one embodiment of the present invention shown in Figure 3 has an end module E at one end of the longitudinal end of a long substrate 1 and a connecting unit JO at the other end. By connecting the end module E and the connecting unit, it is possible to connect two or more measuring units Mes of the measuring system of the present invention to configure a measuring system with a longer measuring unit. Furthermore, in order to simplify the connection structure between the connecting unit JO and the end module E, a wiring crossing unit CR is provided to cross the voltage line V or detection line D, which are provided for connecting to the sensor element S of the extended measuring unit Mes, in a three-dimensional manner. Figure 4 is a schematic diagram of another embodiment relating to the wiring of the measuring section Mes of the measurement system of the present invention.

[0020] (long base material) The elongated substrate 1 in the measuring section Mes of the measurement system of the present invention is not particularly limited as long as it has the function and flexibility of a substrate and is elongated in shape. For example, elongated substrates can be in the form of an elongated film (tape), ribbon, rod, or thread. The elongated substrate may be linear or may have branches along its length. For example, it can be Y-shaped, F-shaped, comb-shaped, tree-shaped, etc. If the elongated substrate has branches, it is possible to perform measurements in two or three dimensions. Furthermore, it is possible to combine elongated substrates to form twisted yarn, mesh, three-dimensional mesh, etc. In the present invention, from the viewpoint of the strength, flexibility, and minimum radius of curvature of the measuring part Mes, for example, an elongated film (tape) shaped substrate with a short side of 100 mm or less, preferably 50 mm or less and 5 mm or more, a long side of 500,000 mm or less, preferably 200,000 mm or less and 50 mm or more, and a thickness of 0.001 mm to 10.0 mm, preferably 0.01 mm to 3.0 mm, can be suitably used.

[0021] The material of the elongated substrate 1 is not particularly limited as long as it is flexible and insulating. Examples include insulators such as resin, paper, cloth, glass, and ceramics that are flexible. Resin film is preferred because it is easy to impart the desired physical properties, has excellent flexibility, and allows for a small minimum radius of curvature. As the resin constituting the resin film, for example, polyester resins, polyamide-imide resins, polyimide resins, polyamide resins, polyetheretherketone resins, polysulfone resins, polyphenylene sulfide resins, polysulfone resins, polyethersulfone resins, fluororesins, ABS resins, polyphenylene oxide resins, acrylic resins, polycarbonate resins, polybutadiene resins, polyurethane resins, polyolefin resins, polyvinyl chloride resins, polystyrene resins, etc., can be used without particular limitation. Furthermore, these resins may be mixtures, and may optionally contain functional materials such as colorants, ultraviolet absorbers, infrared reflectors, and light-scattering particles. Furthermore, these resins, paper, cloth, glass, and ceramics may be combined in any way to form laminates. The color of the long substrate 1 is not particularly limited and may be colorless, colored transparent, translucent, or opaque. It can be appropriately selected depending on the application and installation location of the measurement system Sys.

[0022] (wiring) The wiring in the measuring section Mes of the measurement system of the present invention is provided on a long substrate 1 and extends in the longitudinal direction, and consists of at least m voltage lines V1~V m And at least n detection lines D1~D n The device has the following characteristics: Here, m and n are each independent integers of 2 or more, and are not particularly limited as long as they are within the range that can be formed on the elongated substrate 1 and the number of sensor elements S provided in the measuring section Mes. For example, m and n are each independent integers of 3 or more and 3,000 or less, preferably each independent integer of 4 or more and 1,000 or less, and more preferably each independent integer of 4 or more and 100 or less. Here, the ratio of the number of sensor elements to the number of wires can be maximized when n = m. More than m voltage lines and more than n detection lines may be used to connect to an additional measuring unit Mes. Furthermore, the wiring may be formed by combining multiple layers, each having an arbitrary number of voltage lines V and / or detection lines D. The wiring is composed of conductive materials that include one or more selected from the group consisting of metallic materials such as gold, silver, copper, aluminum, tin, nickel, and chromium; transparent conductive materials such as indium-doped tin oxide and fluorine-doped tin oxide; conductive polymers; conductive carbon; graphene; and carbon nanotubes.

[0023] The wiring has a width of, for example, 0.01 mm or more, preferably 0.03 mm or more, more preferably 0.1 mm or more, and for example, 3.0 mm or less, preferably 2.0 mm or less, more preferably 1.0 mm or less. If the wiring width is less than 0.01 mm, it may become difficult to create the wiring, and when the measuring section Mes is deformed, the wiring may break due to the stress generated. If the wiring width exceeds 3.0 mm, the number of wires (value of n) cannot be increased, which reduces the number of sensor elements S placed on the measuring section Mes, potentially worsening the accuracy of the measurement.

[0024] The wiring has a thickness of, for example, 0.05 μm or more, preferably 0.1 μm or more, more preferably 0.5 μm or more, and for example, 1000 μm or less, preferably 500 μm or less, more preferably 100 μm or less. In the measurement system of the present invention, the measurement section Mes has a relatively rigid joint between the wiring and the sensor element S, allowing the sensor element S to bend and exhibit flexibility in the unjointed portion. When the flexible measurement section Mes is bent, stress is applied to the joint between the wiring and the sensor element S. Therefore, if the wiring thickness is less than 0.05 μm, the resistance value will increase, potentially resulting in insufficient sensing accuracy. On the other hand, if the wiring thickness exceeds 1000 μm, the wiring becomes more rigid, potentially reducing the flexibility of the measurement section Mes and increasing the minimum radius of curvature.

[0025] The method for providing the wiring on the elongated substrate 1 is not particularly limited. For example, the circuit may be formed by printing conductive ink. While the printing method is not particularly limited, screen printing, inkjet printing, gravure printing, offset printing, flexographic printing, dispenser printing, gravure offset printing, and pad printing are preferred. By forming the circuit through printing, mass production becomes possible easily and inexpensively. Examples of conductive inks that can be used include conductive inks containing metal particles, conductive inks containing conductive carbon particles such as carbon black, carbon nanotubes, and graphene, conductive oxides such as indium-doped tin oxide, and conductive polymers. Alternatively, the plating may be formed by creating a plating resist using printing or other means, followed by plating, or by printing a plating seed layer and then plating. Such methods also allow for inexpensive and easy mass production. Furthermore, the conductive layer may be formed by one or more methods selected from the group consisting of metal deposition, plating, silver salt, etc. The formed conductive layer may be further trimmed by means of a laser or other means to form a wiring layer with higher precision.

[0026] One end of the wiring is connected to an end module E provided at one end of the longitudinal side of the elongated substrate 1. Alternatively, as shown in Figure 3, the other end of the wiring may be a connecting section JO. The connecting section JO is for joining with the end module E of another measuring section Mes, thereby enabling the formation of a longer measuring section. In this case, to simplify the connection structure between the connecting section JO and the end module E, a wiring crossing section CR can be provided, which crosses the voltage line V or detection line D, which are provided for connecting to the sensor element S of the extended measuring section Mes, in a three-dimensional manner. In this way, when multiple measuring units (Mes) are used in combination, repairs in the event of a malfunction only require replacing the faulty measuring unit (Mes), making it inexpensive and easy to maintain.

[0027] Furthermore, when a long measuring section Mes is constructed, the sensor element S may become more susceptible to picking up electrostatic induction noise and electromagnetic induction noise. Electromagnetic shielding is an effective countermeasure against electrostatic induction noise. For electromagnetic induction noise countermeasures, as shown in Figure 4, for example, it is effective to form the voltage line and detection line on separate layers and to extend the voltage line and detection line in a meandering manner along the longitudinal direction of the long substrate 1 (a pseudo-twist structure).

[0028] (Sensor element) The sensor element S provided in the measuring section Mes of the measurement system of the present invention is appropriately selected according to the object to be measured and the application, and is not particularly limited. For example, it may be one or more types selected from sensor elements such as temperature, humidity, illuminance, pressure, light, photoelectric, proximity, shear force, magnetism, laser, microwave, strain, gyroscope, acceleration, atmospheric pressure, geomagnetic field, displacement, gas, GPS, ultrasound, sound, odor, electroencephalogram, electric current, vibration, pulse wave, electrocardiogram, electromyogram, light intensity, atmospheric pressure, and biometric sensors. The measuring unit in the measurement system of the present invention is equipped with one or more of these sensor elements, depending on the object to be measured.

[0029] In the measurement unit Mes of the measurement system of the present invention, the number of sensor elements S placed on the elongated substrate 1 is 4 or more and m × n (where m is the number of voltage lines and n is the number of detection lines). m and n are each independent integers of 2 or more, and are not particularly limited as long as they are within the range of the number of sensor elements S required by the measurement unit Mes and the number of sensor elements S that can be placed on the elongated substrate 1. For example, m and n are each independent integers of 3 or more and 3,000 or less, preferably each independent integer of 4 or more and 1,000 or less, and more preferably each independent integer of 4 or more and 100 or less.

[0030] The arrangement of sensor elements S placed on the elongated substrate 1 is not particularly limited. They can be placed on the elongated substrate 1 such that there are a number of sensor elements S in the longitudinal direction and b number of sensor elements S in the short direction or circumferential direction (where a is an integer of 3 or more, b is an integer of 1 or more, and a > b). In particular, the value of b for the number of sensor elements S placed in the short direction is 4 or less, preferably 3 or less, more preferably 2 or less, and most preferably 1 (i.e., the sensor elements S are arranged in a single row in the longitudinal direction of the elongated substrate 1). The number and arrangement of sensor elements S can be adjusted considering spatial resolution.

[0031] Each sensor element S has m voltage lines V1~V m and n detection lines D1~D n The voltage lines and detection lines are connected in such a way that their combinations are different from each other. In the measuring unit Mes having three voltage lines V1 to V3, three detection lines D1 to D3, and nine sensor elements S1 to S9 shown in Fig. 2, the voltage lines and detection lines connected to each sensor element S are as shown in Table 1 below, for example.

[0032] [Table 1]

[0033] (End Module) The end module E in the measuring unit Mes of the measuring system of the present invention has a connector unit having connectors (connection terminals) respectively connected to wiring having at least m voltage lines and at least n detection lines. The connector unit may further have a shielding ground (GND) terminal. The pitch of the connectors (connection terminals) is not particularly limited. For example, it is 5.0 mm or less, preferably 3.0 mm or less, and for example, it is 0.01 mm or more, preferably 0.1 mm or more. The measuring unit is connected to a calculation unit, a detection unit, a bias unit, etc. via the connector unit. In addition, a plurality of measuring units Mes can be connected via the connector unit to configure a measuring system including a long measuring unit.

[0034] The end module E can individually read the measurement values of each sensor element, for example, as follows. In the measuring unit Mes having three voltage lines V1 to V3, three detection lines D1 to D3, and nine sensor elements S1 to S9 shown in Fig. 2, only voltage line V1 is applied with a positive voltage V a , and voltage lines V2 and V3 are set to 0 V (zero volts). At this time, by measuring the currents I1, I2, and I3 respectively flowing through detection lines D1, D2, and D3, the resistance values of sensor elements S1, S2, and S3 can be obtained as V a / I1, V a / I2 and V aIt can be calculated as / I3. However, if the wiring resistance cannot be ignored, the measured values ​​(resistance values) of each sensor element read here will include the wiring resistance, and therefore cannot be said to be accurate values.

[0035] <Calculation part> The calculation unit Cal in the measurement system of the present invention corrects the electrical impedance value data corresponding to each sensor element output from the end module E of the measurement unit Mes by inverse analysis calculation. The electrical impedance value data corresponding to each sensor element output from the end module E of the measurement unit Mes includes the electrical impedance value measured at each sensor element, as well as the electrical impedance value corresponding to the wiring resistance (wiring resistance value). The calculation unit Cal in the measurement system of the present invention is for compensating (canceling) the influence of the electrical impedance value corresponding to the wiring resistance (wiring resistance value) from the electrical impedance values ​​from each sensor element output from the end module E of the measurement unit Mes.

[0036] The calculation unit can be installed in, for example, a computer, a mobile phone (smartphone), a portable information terminal, a database, a cloud system, etc. The location of the calculation unit Cal is not particularly limited, as long as it can receive data from the measurement unit Mes. For example, the calculation unit can be configured to receive data transmitted using communication means from the end module E of the measurement unit Mes or the communication unit connected thereto. Alternatively, the calculation unit can be configured to be connected by wires to the end module E of the measurement unit Mes or each of the units connected thereto.

[0037] The calculation unit Cal can be configured to connect to the end module E of the measurement unit Mes, as shown in Figure 1. Alternatively, it can be configured within the end module E of the measurement unit Mes. Furthermore, it can be connected to one or more of the detection unit, recording unit, etc., which are connected to the end module E, and can also be configured inside each of these units.

[0038] Figure 6 is a flowchart illustrating one embodiment of the operation of the calculation unit Cal. After starting, it proceeds through steps S01 to S08 and then terminates.

[0039] Step S01 is the data input stage to the calculation unit. In step S01, the calculation unit receives data that is the sum of the data measured by the measurement unit and the wiring resistance value data. Data input from the measurement unit to the calculation unit can be done via wired or wireless connection, or via a storage medium.

[0040] Step S02 is the stage of creating an equivalent circuit model. An example of an equivalent circuit model to be created is the equivalent circuit model shown in Figure 8 or Figure 9.

[0041] Step S03 is the stage in which the matrix A used in the inverse analysis calculation is initially estimated based on the equivalent circuit model created in step S02.

[0042] Step S04 is the stage in which the matrix A, which was initially estimated in step S03, is updated by taking various factors into consideration.

[0043] Step S05 is the stage for determining the convergence of matrix A. When determining convergence, at least one of the following is considered: the number of times matrix A has been updated up to the point of convergence (the number of loops in steps S04 to S05) and the residual of the equation (left side - right side). If, during the stage of determining the convergence of matrix A, it is determined that convergence is not possible, the process returns to step S04 and matrix A is updated. In the step of determining the convergence of matrix A, if it is determined that convergence is possible, the process proceeds to step S06 to finalize matrix A.

[0044] Step S06 is the stage in which matrix A is determined. The determined matrix A is used in step S07 to calculate the sensor element electrical impedance value (resistance value) by inverse analysis calculation.

[0045] Step S07 is a process of calculating the electrical impedance value (resistance value) of the sensor element itself by using matrix A determined in step S06 and compensating (canceling) for the effect of wiring resistance.

[0046] Step S08 is the process of calculating a physical quantity based on the electrical impedance value (resistance value) of the sensor element itself, which is obtained by compensating (canceling) the effect of wiring resistance. Once the physical quantity is calculated, the operation of the calculation unit is completed.

[0047] Conventional passive matrix sensors assume that wiring resistance is negligible. Therefore, their equivalent circuit model is represented as shown in Figure 7, and bias voltage values ​​U1~U are applied to one of the horizontal wires. m When one of these voltages is applied and the other is set to 0V, the resistance value R of the sensor element ij The measured current value is J i As R ij =U i / J i The value is calculated using the following method.

[0048] However, when wiring is formed using a conductive paste (e.g., conductive carbon black paste), the wiring resistance becomes a value that cannot be ignored. In such cases, the equivalent circuit model of the passive matrix sensor can be represented as shown in Figure 8. In this case, the sensor element resistance value R ij , horizontal wiring resistance value S ij and vertical wiring resistance value T ij The total resistance value Z is the sum of the values. ij Current value J1···J n The problem of finding the values ​​can be reduced to a system of equations and easily solved numerically. Solving the inverse problem, that is, the measured current values ​​J1, ..., J n By determining the resistance value that reproduces the sensor element resistance R of any sensor element, ij You can obtain the value.

[0049] In Figure 8, the sensor element resistance value R is determined by current measurement.ij The resistance value R of the sensor element was determined by voltage measurement. ij When determining the equivalent circuit model, the sensor element resistance R can be represented as shown in Figure 9, and the sensor element resistance R can be determined by current measurement. ij Using a method similar to the one used to determine the resistance value R of an arbitrary sensor element, ij It is possible to find this.

[0050] A specific inverse analysis calculation method can be performed, for example, by setting up Kirchhoff's first law equation for each node in the circuit. That is, if the number of equations obtained by setting up Kirchhoff's first law equation for each node is greater than or equal to the number of unknown variables, then it is possible to find the unknown variables by solving the system of equations. Kirchhoff's first law equation can be formulated for internal nodes that are not connected to the outside and for measuring nodes that measure current. Specifically, it can be done as follows:

[0051] The general method for inverse analysis calculations is as follows: The nodes in the circuit are classified into M bias nodes that apply bias, N measurement nodes that measure current, and L other internal nodes. Only resistive elements are connected between each node, and the reciprocal of the resistance connecting the internal nodes is f. ij g is the reciprocal of the resistance connecting the internal node and the bias node. ij h is the reciprocal of the resistance connecting the internal node and the measurement node. ij Let f be the case. ii =0,f ii =f ji Furthermore, for simplicity, we assume there is no resistance between bias nodes, between measurement nodes, and between bias nodes and measurement nodes.

[0052] The potential of the bias node is u i , the potential of the internal node v i The potential of the measurement node is set to 0, and the current flowing out of the measurement node is set to j. iTherefore, applying Kirchhoff's first law, the following applies to the internal node and the measurement node: (1), (2):

number

number

number

[0053] When the potential of the bias node is changed and measurements are taken M times, different v i u i , j i m of each are obtained, and then v im u im , j im Then, equations (4) and (5):

number

number

[0054] Here, P is a square matrix and is usually invertible, so V = -P -1 Eliminating V using QU gives the following equation (8): J=-RP -1 QU (8) You can obtain this.

[0055] This equation allows us to explicitly determine the current J once the total resistance is known (a forward problem). On the other hand, since this equation is a system of MN equations, if matrices U and J are measured, the variables f included in matrices P, Q, and R can be determined. ij, g ij h ij If the number of unknown variables is less than or equal to MN, these can be determined by inverse analysis (inverse problem).

[0056] Based on the general inverse analysis calculations described above, the inverse analysis calculation for a passive matrix can be performed as follows. Consider the case of a passive matrix consisting of m × n pixels, as shown in Figure 8. In this case, M=m, N=n, and L=mn. When m measurements are taken with a linearly independent bias pattern, mn independent equations are obtained. If the wiring resistance is 0 or known, then f ij There are mn unknown variables among them, g ij h ij Since is known, all unknown variables can be determined.

[0057] If we divide the internal nodes into nodes X on the horizontal wiring and nodes Y on the vertical wiring, then equations (5) and (6) become equations (9) and (10):

number

number

[0058] Expanding this, we get the following equations (11), (12), (13): P XX X+P XY Y+Q X U=0 (11) P YX X+P YY Y=0 (12) R Y Y=J (13) This can be done. Here, P XX The contribution due to the sensor element resistance is A (diagonal matrix), the contribution due to the horizontal wiring resistance is B, and P YY The contributions of vertical wiring resistance are denoted as C and -Q. X U to D, R Y Let E be the following equations (14), (15), (16): (A+B)X-AY-D=0 (14) -AX+(A+C)Y=0 (15) EY=J (16) It can be done this way.

[0059] Eliminating X and Y, we get equations (17), (18), and (19): E(BA -1 C+B+C) -1 D=J (17) EC -1 (A -1 +B -1 +C -1 ) -1 B -1 D=J (18) EC -1 (I+(B -1 +C -1 )A) -1 AB -1 D=J (19) By solving this using successive methods such as Newton's method, P XX The contribution A due to the sensor element resistance can be determined.

[0060] Here, we have the zero-order approximation A of A. (0) of

number

[0061] Figure 10 shows the simulation results for the case where the wiring resistance is 1 / 10 of the sensor element resistance, specifically the resistance distribution without considering the wiring resistance (A), the true resistance distribution (B), and the resistance distribution corrected by inverse analysis calculation (C). Figure 11 shows the simulation results for the resistance distribution without considering the wiring resistance (A), the true resistance distribution (B), and the resistance distribution corrected by inverse analysis calculation (C), for the case where the wiring resistance is approximately the same as the sensor element resistance. As shown in Figures 10 and 11, by correcting the resistance values ​​through inverse analysis calculations, it is possible to obtain a resistance distribution that is almost equivalent to the true resistance distribution, even in the presence of wiring resistance.

[0062] <Connected equipment, etc.> The measurement system of the present invention allows various devices to be connected via the connector portion of the end module E of the measurement unit Mes. Examples of devices to be connected include one or more of the following: a detection unit, a bias unit, a power supply, a recording unit, a display unit, etc. At least some of these can be integrated and incorporated with the end module E. Furthermore, the calculation unit can also be incorporated into these devices.

[0063] The detection unit is the part that decomposes the electrical signal sent from the sensor element S via the detection line D and generates measurement data. The current range, current resolution, internal resistance, and recommended resistance value of the sensor can be set as appropriate. For example, the current range can be set to 30 to 300 μA, the current resolution to 1 / 65536 of the maximum current range (0.46 to 4.6 nA), the internal resistance to 100 Ω, and the recommended resistance value of the sensor element S to 20 to 200 kΩ.

[0064] The bias section is for supplying a bias voltage to the sensor element S. The bias voltage (output voltage) is not particularly limited, and a suitable voltage can be set according to the sensor element S, etc. For example, the bias voltage (output voltage) is 1.0V or higher, preferably 2.5V or higher, and for example, 5.0V or lower, preferably 4.0V or lower.

[0065] Examples of power sources include batteries such as button batteries, dry cell batteries, and lithium-ion batteries, power generation devices such as solar power generation equipment, and industrial or household AC power supplies. These power sources may be incorporated into the end module E, for example, or connected via USB or a power outlet. The voltage supplied from the power supply is not particularly limited and can be set to a range of, for example, 3.0V to 21V. The current consumption is not particularly limited and can be set to a range of, for example, 10mA to 100mA.

[0066] Examples of recording units include computer devices with memory elements, and examples of display units include display devices. The measurement data generated by the detection unit is transmitted to these recording and display units, and the communication method may be wired or wireless.

[0067] <Applications of the measurement system, etc.> The measurement system of the present invention can be used for a wide variety of applications depending on the type of sensor element S. Furthermore, the measurement system of the present invention can be used for applications that take advantage of the flexibility of its measurement unit. Applications of the measurement system of the present invention include, for example, the management of temperature, humidity, illuminance, etc., in agricultural facilities, industrial plants, pipelines, computer (server) rooms, storage facilities for pharmaceuticals and food, etc. It can also be used for the management of temperature, humidity, etc., inside bedding and clothing. Furthermore, it can be used as a wearable sensor for health management and medical management, such as a mobile device attached to the human body or animals.

[0068] <Manufacturing method for the measurement system> There are no particular limitations on the method for manufacturing the measurement system of the present invention. A measurement system can be manufactured by providing a measurement unit and a calculation unit by any arbitrary means.

[0069] An example of a method for manufacturing the measurement unit of the measurement system of the present invention is as follows: (1) a step of providing, on an elongated base material 1, at least m voltage lines V1 to V extending in the longitudinal direction of the elongated base material 1 m and at least n detection lines D1 to D n a step of providing a wiring layer L1 having (2) a step of providing an insulating layer L2 having via holes on the wiring layer L1 (3) a step of providing an electrode layer L3 having not more than m×n electrodes on the insulating layer L2 (4) a step of providing the electrode layer L3 (5) a step of providing a sensor element S on the electrode layer L3 (6) a step of providing an end module E connected to the wiring on one of the longitudinal end portions of the elongated base material 1 includes at least the via holes of the insulating layer L2 connect each electrode of the electrode layer to the voltage line and the detection line such that combinations of at least m voltage lines V1 to V m and at least n detection lines D1 to D n are different from each other A method for manufacturing the measurement unit is given above. FIG. 5 is a diagram illustrating at least steps (1) to (3).

[0070] The wiring layer L1 has at least m voltage lines V1 to V on the elongated base material 1 m and at least n detection lines D1 to D n is formed by providing. FIG. 5 illustrates an embodiment in which four voltage lines V1 to V4 are provided so as to be sandwiched in the width direction of the elongated base material 1 by two detection lines D1 to D2 and two detection lines D3 to D4. There are no particular limitations on the means for providing the wiring layer L1 on the elongated base material 1. For example, at least m voltage lines V1 to V m and at least n detection lines D1 to D nThe circuits can be formed by printing conductive ink. While the printing method is not particularly limited, screen printing, inkjet printing, gravure printing, offset printing, flexographic printing, dispenser printing, gravure offset printing, and pad printing are preferred. By forming the circuits through printing, mass production becomes possible at low cost, easily, and at high speed. Alternatively, the plating may be formed by creating a plating resist using printing or other means, followed by plating, or by printing a plating seed layer and then plating. Such methods also allow for inexpensive and easy mass production. Furthermore, it may be formed by one or more methods selected from the group consisting of metal deposition, plating, silver salt, etc.

[0071] The wiring layer L1 has at least m voltage lines V1~V m The layer in which the line is set and at least n detection lines D1~D n It may consist of two or more layers, including a layer in which the lower wiring layer L is provided. In such a case, for example, the lower wiring layer L 11 After forming the lower wiring layer L 11 An intermediate layer made of an insulator is formed on top of the intermediate layer, and an upper wiring layer L is placed on top of the intermediate layer. 12 By forming this, the wiring layer L1 can be formed. In addition, holes are formed in the intermediate layer that communicate with via holes provided in the insulating layer L2.

[0072] The insulating layer L2 is formed by providing an insulating film on the wiring layer L1, with via holes formed at predetermined positions to serve as connection points with the electrodes. Furthermore, at least one end of the elongated substrate 1 in the longitudinal direction is formed as an end module installation section Es by ensuring that the insulating layer L2 does not cover the electrode layer. Figure 5 shows one embodiment in which an insulating film 201 is provided with via holes 202 that connect each electrode of the electrode layer to the voltage lines and the detection lines, such that the combinations of the four voltage lines V1 to V4 and the four detection lines D1 to D4 are different from each other, and an end module installation section Es is provided at at least one end of the elongated substrate 1 in the longitudinal direction. The means for providing the insulating layer L2 having via holes are not particularly limited. For example, it can be formed by printing insulating layer forming ink. The printing method is not particularly limited, but screen printing, inkjet printing, gravure printing, offset printing, and flexographic printing are preferred. By forming the circuit by printing, it becomes possible to mass-produce inexpensively, easily, and at high speed. The size of the via holes is not particularly limited, but can be appropriately adjusted according to the thickness of the voltage line V and the detection line D. For example, the diameter can be approximately the same as the thickness of the voltage line V and the detection line D. When providing the insulating layer L2 having via holes, at least one of the shorter sides of the measurement section is designated as the end module installation section Es.

[0073] The electrode layer L3 is formed on the insulating layer L2 by providing voltage line connection electrodes and detection line connection electrodes at predetermined positions. As shown in Figure 5, the electrodes provided in the electrode layer consist of a pair of electrodes: a voltage line connection electrode 301 that connects to the voltage line via a via hole, and a detection line connection electrode 302 that connects to the detection line via a via hole. The means for providing the electrode layer L3 are not particularly limited. The same means as for providing the wiring layer L1 can be used.

[0074] Means for providing a sensor element on an electrode layer include, for example, soldering, bonding with conductive adhesive, bonding with nanoparticles, and bonding by fitting. Among these, solder joints include, for example, solder flow, solder reflow, and solder joints using lead-free solder and electromagnetic induction heating (IH) technology.

[0075] In the present invention, after providing the electrode layer L3 or the sensor element S, the invention may optionally include a step of providing a resistive layer L4. When providing the resistive layer L4, the means for doing so are not particularly limited. For example, the same means as for providing the insulating layer L2 can be used.

[0076] [program] The computer program according to the present invention is for enabling a computer to function as a measurement system. Examples of computers include personal computers, mobile phone terminals (smartphones), and portable information devices. This allows users to easily participate in the measurement system from their own computer terminals via communication lines. Computer programs can be distributed and installed on computers via download from the cloud, or they can be distributed and installed on computers while stored on a suitable medium. [Examples]

[0077] A carbon black printed wiring was formed on a polyethylene naphthalate film by screen printing a carbon black-containing conductive ink, and an insulating layer was formed by printing polyvinyl alcohol ink with a dispenser. Then, sensor elements (NTC thermistors) were mounted using stretchable silver paste to create the 2x2 passive matrix sensor array shown in Figure 12. The stretchable silver paste was prepared based on Nat. Commun. 6, 7461, 2015 (https: / / www.nature.com / articles / ncomms8461), and consists of silver flakes, fluororubber, fluorosurfactant, and 4-methyl-2-pentanone.

[0078] For each sensor element (R11, R12, R21, and R22), the wiring resistance was measured in advance at room temperature (26°C). Then, the entire circuit board was heated on a hot plate in the range of 26°C to 140°C. 3.3V was applied to terminals T1 or T2 at the end of the wiring 12 times at 10°C intervals from 30°C to 140°C, and the current was measured at terminals T3 and T4. The resistance value of each sensor element before correction, without canceling the effect of wiring resistance, was calculated using the voltage / current ratio. Furthermore, the corrected resistance value of each sensor element, after canceling the effect of wiring resistance, was calculated based on inverse analysis calculations. The calculated values ​​are shown in Figure 13. As shown in Figure 13, the resistance values ​​of each sensor element before correction, without canceling the effect of wiring resistance, were significantly higher than the theoretical values ​​due to the influence of wiring resistance. This was particularly noticeable in the high-temperature region where the resistance of the sensor element (thermistor) decreases, and in sensor element R11, which has long wiring. On the other hand, the resistance values ​​of each sensor element after correction, with the effect of wiring resistance canceled, were in good agreement with the theoretical values. Although the wiring resistance using carbon black-containing conductive ink was approximately 4.8 times that of the sensor element, it was still possible to obtain the resistance value of a normal sensor element. Here, "theoretical value" refers to temperature T n Resistance value R n Therefore, it can be calculated from the reference temperature T0 (=25°C), the thermistor's resistance R0 at the reference temperature, and the thermistor's B constant based on the following formula.

number

[0079] Although the present invention has been described in detail above, various modifications can be made to the above configuration without departing from the scope of the invention. Therefore, all matters included in the above description or shown in the accompanying drawings should be construed as illustrative. [Explanation of Symbols]

[0080] Sys: Measurement System Mes: Measuring part Cal: Calculation part 1: Long base material S: Sensor element E: End Module V, V1~V8: Voltage lines D, D1~D8: Detection lines CR: Voltage line - detection line intersection JO: Connection part L1: Wiring layer L2: Insulating layer L3: Electrode layer L4: Resistance layer 201: Insulating film 202: Beer Hall Es: End module installation section 301: Voltage line connection electrode 302: Detection line connection electrode R 11 , R 21 ..., R m1 , R 12 ..., R 1n ..., R mn : Sensor resistance U1, U2, ..., U m Bias voltage J1, J2, ..., J n :Current (measured current) S 11 S 21 , , , S m1 S 12 , , , S 1n , , , S mn : Horizontal wiring resistance T 11 , T 21 , , , T m1 , T 12 , , , T 1n , , , T mn : Vertical wiring resistor V1, V2, ..., V n Voltage (measured voltage) W1, W2, ..., W n Voltage measuring instrument resistance Ra11: NTC thermistor (R11) Ra12: NTC thermistor (R12) Ra21: NTC thermistor (R21) Ra22: NTC thermistor (R22) CBL: Carbon Black Printed Wiring T1: Terminal (T1) T2: Terminal (T2) T3: Terminal (T3) T4:Terminal (T4)

Claims

1. A measurement system comprising a measurement unit that uses electrical impedance values ​​and a calculation unit that corrects electrical impedance values ​​using inverse analysis calculations.

2. The measurement system according to claim 1, wherein the calculation unit compensates for the effect of wiring resistance.

3. The measurement system according to claim 1, wherein the measurement unit comprises a flexible ribbon-type multi-point sensor.

4. The measurement system according to claim 1 or 2, wherein the measurement unit comprises one or more selected from a temperature sensor, humidity sensor, illuminance sensor, pressure sensor, light sensor, photoelectric sensor, proximity sensor, shear force sensor, magnetic sensor, laser sensor, microwave sensor, strain sensor, gyro sensor, acceleration sensor, geomagnetic sensor, displacement sensor, gas sensor, GPS sensor, ultrasonic sensor, sound sensor, odor sensor, taste sensor, electroencephalogram sensor, current sensor, vibration sensor, pulse wave sensor, electrocardiogram sensor, electromyogram sensor, light intensity sensor, barometric pressure sensor, and biosensor.

5. A program that causes a computer to function as a calculation unit in the measurement system described in claim 1.

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